jQuery 1.5 Released

This release has been a long time coming and has been a real team effort. Please take this opportunity to thank members of the jQuery Team and the jQuery bug triage team for their help in getting this release out the door.

Downloading

As usual, we provide two copies of jQuery, one minified and one uncompressed (for debugging or reading).

A full schedule of our upcoming releases can be found on our roadmap. Right now we’re planning on doing major jQuery releases more frequently (likely a couple times a year, rather than once per year).

So, without further ado, what’s changed in jQuery 1.5?

Ajax Rewrite

Easily the largest change in this release is the complete rewrite of the Ajax module in jQuery. This rewrite helps to fix a lot of gaps that existed in the old Ajax system along with providing a higher level of consistency across the API.

Perhaps the largest change is that a call to jQuery.ajax (or jQuery.get, jQuery.post, etc.) now returns a jqXHR object that provides consistency to the XMLHttpRequest object across platforms (and allows you to perform previously-impossible tasks like aborting JSONP requests).

In addition to a more consistent API the Ajax system is now much more extensible – allowing you to attach all sort of data handlers, filters, and transports. These changes should open up a whole realm of new Ajax plugins that can take advantage of this extensibility. More information can be found in the Extending Ajax documentation. The team is actively soliciting feedback on the Ajax extensibility API and if you have any feedback please feel free to direct it to the Developing jQuery Forum.

Deferred Objects

Along with the rewrite of the Ajax module a new feature was introduced which was also made publicly available: Deferred Objects. This API allows you to work with return values that may not be immediately present (such as the return result from an asynchronous Ajax request). Additionally it gives you the ability to attach multiple event handlers (something that wasn’t previously possible in the Ajax API).

For example, the following is now possible with jQuery’s internal Ajax API:

jQuery now exposes a new way in which you can create and modify a clone of jQuery – all while still taking advantage of the full jQuery API. For example, you could use it to override native jQuery methods without actually affecting the methods that other users would interact with – or even create encapsulated APIs for your plugins that avoid namespace collision.

Here is a sample of adding a method to a jQuery sub so that it isn’t exposed externally:

More information about jQuery.sub() can be found in the API documentation.

Note that if you’re looking to use this for plugin development, you should first strongly consider using something like the jQuery UI widget factory which manages both state and plugin sub-methods. Some examples of using the jQuery UI widget factory to build a plugin.

Adjacent Traversal Performance

In this release we’ve also been able to improve the performance of some commonly-used traversal methods: .children(), .prev(), and .next(). The speed-ups that we’re seeing are quite substantial (potentially many many times faster, depending upon the browser).

Build System

Finally, we’ve made some changes to jQuery’s internal build system. We’ve worked to standardize all of our build process upon the excellent server-side JavaScript environment: NodeJS. We especially appreciate this as we’re able to reduce our dependency upon legacy Java/Rhino systems and focus more squarely on up-and-coming JavaScript environments.

Additionally with this switch we’ve moved to using UglifyJS from the Google Closure Compiler. We’ve seen some solid file size improvements while using it so we’re quite pleased with the switch.

Thanks!

As always we want to thank everyone that helped with this release – without your contributions this release would not have been possible. If you have any questions or spot any bugs please submit your issues to the jQuery bug tracker.